Simplify the following expression: $x = \dfrac{10k^2 + 20k - 800}{k - 8} $
Explanation: First factor the polynomial in the numerator. We notice that all the terms in the numerator have a common factor of $10$ , so we can rewrite the expression: $ x =\dfrac{10(k^2 + 2k - 80)}{k - 8} $ Then we factor the remaining polynomial: $k^2 + {2}k {-80} $ ${-8} + {10} = {2}$ ${-8} \times {10} = {-80}$ $ (k {-8}) (k + {10}) $ This gives us a factored expression: $\dfrac{10(k {-8}) (k + {10})}{k - 8}$ We can divide the numerator and denominator by $(k + 8)$ on condition that $k \neq 8$ Therefore $x = 10(k + 10); k \neq 8$